1. Field
One embodiment of the invention relates to a video processing apparatus and a video processing method for reproducing moving image data.
2. Description of the Related Art
In recent years, opportunities to view moving image data reproduced by an electronic apparatus such as a personal computer or a video recorder have been increasing. Examples of moving image data to be reproduced include not only those recorded in DVDs or recorded broadcast program data broadcast via television broadcast signals but also those downloaded from moving image data sharing sites on the Internet. Thus, electronic apparatuses such as personal computers and video recorders need to provide a reproduction function corresponding to moving image data in various formats such as MPEG-2 (H.262|MPEG-2), MPEG-4, and MPEG-4 AVC (H.264|MPEG-4 AVC).
Jpn. Pat. Appln. KOKAI Publication No. 11-355728 discloses an audio/video synchronous reproduction method of controlling synchronization between audio and video without the use of a frame rate described in video data. The audio/video synchronous reproduction method calculates the time difference between the latest time stamp and the preceding time stamp and the number of frames between the time stamps using frames, each of which are added time stamps, in video data. The audio/video synchronous reproduction method then calculates the frame rate using the time difference and the number of frames.
It may not be essential to add information on reproduction timings to moving image data for each processing target unit such as GOP. For example, moving image data in the MPEG-4 AVC (H. 264|MPEG-4 AVC) format allows the use of even GOP not including information on reproduction timings. Thus, for example, if moving image data such as a live stream starts to be reproduced from the middle of the stream, the moving image data may not be smoothly reproduced due to unknown picture display timings.
Furthermore, for example, moving image data distributed on the Internet may not exactly conform to the standards. Hence, such moving image data may include moving image data without information on reproduction timings. Such moving image data is also difficult to reproduce smoothly because the reproduction timing for the data is unknown.